System of steam propulsion.



E. H. COAPMAN & R. L. ETTENGER.

SYSTEM OF STEAM PROPULSION.

APPLICATION FILED JULY I7. I9I5.

Patented Aug. 14, 1917.

E. H. COAPMAN & R. L. ETTENGER.

SYSTEM OF STEAM PROPULSION.

APPLICATION FILED JULY 17, 19l5.

Patented Aug. 14, 1917.

3 SHEETS-SHEET 2v .PLTLI .THH. LLLEF'LERHL ,i N

wihaeoom H. COAPMAN & R. L. ETTENGER.

SYSTEM OF STEAM PROPULSION.

APPLICATION FILED JULY 17. 1915.

l 23 91 Q o Patented Aug. 14,1917.

3 SHEETS-S HEET 3' UNITED STATES PATENT OFFICE.

EUGENE H. COAPMAN AND ROBERT L. ETTENGER, OF WASHINGTON, DISTRICT OF COLUMBIA.

Specification of Letters Patent.

Patented Aug. 14, 1917.

Application filed July 17, 1915. Serial No. 40,508.

The present invention relates to motive power for railway-cars and consists in the arrangements and combinations of parts hereinafter described and particularly set forth in the accompanying claims.

The locomotive engine has in recent years been increased in size and perfected or refined in its operating parts, though these improvements have, however, not departed from the accepted and. usual practice of having, as a supply tender for each locomotive, an independent car for carrying coal and water; these supply cars being hauled over the road wherever the engine is in service, and frequently weigh as much as' 175,000 pounds, thereby reducing the revenue tonnage an amountequal to their weight.

\Vith the object of eliminating this unremunerative tonnage and increasing the hauling tonnage of the locomotive beyond the equivalent of the supply car and its load, it is proposed to equip and utilize the locomotive supply tender as a tractor, controllable from the cab of the main engine, and without in any manner detracting from its usefulness as a supply car or interfering with the design or construction of the water tank or its coal space. V

The additional tractive power which can be gotten by this arrangement is limited only by the weight of the tank and the amount of steam that can be drawn from the boiler, thereby very materially increasing the hauling capacity of the locomotive to which the tractor is attached, without complicating its design or in any way interfering with the convenience and comfort of its operators, and a very important feature in connection with this improvement is the fact that many li ht locomotives which have been withdrawn rom service on account of defective boilers and are not considered economical to maintain on account of their limited hauling capacity, may now have the old boilers discarded and the cisterns now in use with standard engines can be mounted on the lighter locomotive frames, utilizingthe entire engine to get the increased tractive power at very small expense, it not being necessary to build new equipment to get the benefit of these improvements, although it is felt that advantage will be takenof the idea and many new engines, when built, will for economical reasons follow the system herein disclosed, i. 6., placing a locomotive engine under an ordinary engine cistern and taking superheated or saturated steam from the locomotive boiler on the front engine for operating the rear engine at slow speeds, thereby increasing the tonnage which can be hauled over heavy grades without the assistance of a helping engine. It is claimed that this can be done at small expense by utilizing old engines that would otherwise be discarded, and in the case of new power, at a comparatively small expense over the cost of the ordinary tender frame and trucks.

To increase to the limit the steaming capacity of the boiler, it is proposed to use all of the modern devices for economy, such as superheated steam, fire box arches, feed water heaters, and automatic stokers. These features, while desirable and economical, are not necessary for the operation of the tractor.

It is further contemplated to employ a combination of air and oil cylinders for shifting the links and governing the cut-oif of the tractor engine, although the engine can be operated with the cut-off in a fixed position, but not with the same economy and to as much advantage as can be gotten by using a variable cut-ofl.

The invention is shown by way of illustration in the accompanying drawings,

wherein:

Figure 1 illustrates a mikado engine with its tender mounted on the frame of a mogul engine.

Fig. 2 is a side elevational view thereof, with the main engine and tender broken away, and showing the locomotive equipment on the latter.

Fig. 3 is an elevational view of the steam pipe system for the" tender engine, and the link motion therefor, and

Fig. t is a plan view of the steam pipe connections betweengthe main and auxiliary engines.

Referring to the construction in detail and .With like reference characters indicating corresponding parts, 1 designates an ordinary locomotive having the usual propelling encarrying the tender may well be built as such initially. The arrangement shown herein illustrates merely an expedient for reducing the system to practice, z. e., the utilization of locomotives otherwise withdrawn from service.

A steam pipe 7 connects with the boiler of the main engine or to the super-heater and is fitted with a controlling valve 8 for permanently shutting off the steam supply to the auxiliary engine. A flexible joint 9 couples the steam pipe 7 to the pipe 10 extending to either side of the car, and pipes 11 (one being shown) connect the pipe 10 to the saddles 12 of the respective engine cylinders 13. The exhaust pipe 14 from the cylinders is carried to the rear end of the tender and to the atmosphere.

A link motion of the ordinary Stephenson type is mounted on the frame A of the supply car, and the bell crank, or lift shaft, 14 thereof is actuated from the main engine through air pressure and manual control. A piston operating in theair pressure cylinder 15 has its rod 16 connected to the lift shaft 14* and carries a piston working within the dash pot 17 under a throttling action. Said cylinder 15 is connected to communicate with the train air brake system through the pipes 18 and 19, and is suitably controlled from the main engine for actuating the rod 16 and the lift shaft 14 to control the link motion on the tender. A reach rod 20 is connected to said lift shaft and extends to the front end of the car within convenient reach of the fireman or engineer, and the handle end 21 of said reach rod is notched to engage with a projection on a bracket A spring tensioned presser foot 23 normally holds the rod in set position, andthe free end of the reach rod Works within a protecting hood 23 mounted on the bulkhead 24 of the tender.

The control for the auxiliary engine is by a throttle 2& located within the cab of the locomotive and near the throttle 25 thereof.

In operation the throttle 2% is slightly and lift shaft connections, to adjust the valve to receive steam suflicient to warm up the cylinder, and when the grade is reached the throttle is fully opened and the link motion correspondingly shifted.

In the practical operation of an engine of modern design equipped with tender tractor as described, a draw bar tractive effort is secured that does not at first appear when considering the proposition. In designing locomotives one of the conditions of first importance is to get a boiler of sufficient capacity to provide for the greatest possible sustained horse-power within the limits of weight of the finished engine on its driving wheels, and it is not claimed that a large amount of steam can be economically drawn from the ordinary boiler for auxiliary purposes and still maintain the full value of the leading engine. However, there are times when the engine is running at slow speed on ruling grades that considerable excess steam can be generated, and this steam used as auxiliary power without reducing the mean'efi'ective pressure in the cylinders of the leading engine, but at other times this.

cannot be done, particularly on long grades and where the auxiliary engine must be used a considerable length of time; the gain de rived from the tractive effort of the auxiliary engine, even though the boiler pressure may be reduced, more than equals the loss in the leading engine, and this has been demonstrated in actual service.

As an example, it may be assumed that the-tractor has been attached to a modern freight locomotive using superheated steam at a boiler pressure of 175 pounds. This engine may develop a tractive effort of 51,000 pounds with full boiler pressure, which may be its maximum. Should steam be taken from the boiler to such an extent that the pressure is reduced to say 155 pounds, the tractive effort of the leading engine would then be reduced to 45,800 pounds, but during this reduction of pressure on the leading engine, the auxiliary engine has been using the steam from the boiler of the front engine and developing a tractive effort of about 18,000 pounds, so that the available locomotive power for hauling the train, while decreased for lack of steam in the front engine from 51,000 pounds to 45,800 pounds, is getting the advantage of say 18,000 pounds tractive power from the auxiliary engine, or a net increase in draw bar pull of about 12,800 pounds, and it is due to this fact that fluctuations and reductions in the steam pressure of the front engine are much more than olf-set by the power derived from the auxiliary engine that makes it possible to increase the train haul in certain districts where the grades are favorable, from 25% to 30%, without materially increasing the cost.

Having thus described our invention, what comprising a standard locomotive, a selfcontained locomotive tender coupled to the locomotive and utilizable independently thereof, said tender constructed to contain and present fuel in feeding relation to the generating plant. of said locomotive, a propelling engine carried by the tender, a link motion associated with the engine of the tender, a steam conduit leading from the generating plant of the locomotive to the engine of the tender, and means for controlling the engines of the locomotive and the tender and the link motion of the tender from the locomotive; said tender operable for propulsion in emergency instances and said'locomotive and tender being operable independently.

2. A system of steam propulsion for trains comprising a main vehicle carrying a propelling engine and a steam generating plant, a separable auxiliary vehicle coupled to the main vehicle andv constructed to contain and present fuel in feeding relation to the generatingplant of the main engine, a propelling engine mounted on the auxiliary vehicle, a link motion associated with the pro pelling engine of the auxiliary vehicle, a.

steam conduit leading from the generating plant of the main vehicle to the engine of the auxiliary vehicle, and means for controlling the engines of the main and auxiliary vehicles and the link motion of the auxiliary vehicle from the main vehicle; said auxiliary vehicle operable for propulsion in emergency instances and said locomotive and auxiliary vehicle being operable independently.

3. A system ofsteam propulsion for trains comprising a, main vehicle carrying a pro polling engine and a steam generating plant including a super-heater, a separable auxiliary vehicle coupled to the main. vehicle and constructed to contain and present fuel in feeding relation to the generating plant of the main engine, a propelling engine mounted on the auxiliary vehicle, a link motion associated with the propelling engine of the auxiliary vehicle, a steam conduit leading from the super-heater of the main vehicle to the engine of the auxiliary vehicle, and means for controlling the engines of the main and auxiliary vehicles and the link motion of the auxiliary vehicle from the main vehicle; said auxiliary vehicle operable for propulsion in emergency instances and said locomotive and auxiliary vehicle being operable independently.

'4. A tender for a steam driven locomotive having a frame provided at its ends with castings for carrying respectively the coupling to the locomotive and the draw-bar to the train, a propelling engine mounted on the frame adapted to have steam pipe connection with the generating plant of the locomotive, a link motion associated with the engine, and a reach rod cbnnected to the link motion and having its free end located adj acent the locomotive coupling end of the tender, whereby the engine of the tender will be auxiliary to the locomotive and controllable therefrom; said tender operable for propulsion in emergency instances and said locomotive and tender being operable independently.

5. A system of steam ropulsion for trains comprising a main in ependently operable -vehicle carrying a propelling engine and a steam generating plant including a superheater, an auxiliary vehicle coupled to and operable conjointly with and independently of said main vehicle and constructed to contain and present fuel in feeding relation to the generating plant of the main engine, a propelling engine mounted on the auxiliary vehicle, a steam conduit leading from the super-heater of the main vehicle to the engine of the auxiliary vehicle, and a control for the engines of the main and auxiliary vehicles located on the main vehicle; said auxiliary vehicle operable for propulsion in emergency instances and said locomotive and auxiliary vehicles being operable independently.

In testimony that we claim the foregoing as our own, we affix our signatures in presence of two witnesses.

EUGENE H. ooAPMAN. ROBERT L. ETTENGER. 

